Major depressive d/o Flashcards
What are antidepressants specifically prescribed for?
- Major depressive disorder
- Affective disorders that are characteristized by extreme depression (dysphoria), extreme elation (mania), or both.
- Monopolar depression may affect 15% of all adults during any given year of their lifetime
- Treatment usually takes 2-4 weeks and leads to 85% remission
Affective disorders
- Depression
- Result from a chemical imbalance between 3 NT
- NE, serotonin and perhaps dopamine
- Recent research has suggested that beta-adrenergic receptors may be involved
- Beta blockers often give an antidepressant effect (pts get depressed when they come off of the beta blockers)
As a class of drugs, antidepressants are generally:
- orally administered (IM admin very infrequent and limited to specific drugs)
- very few injectable preparations. Most tx of depression is outpt, so PO is necessary
- 90-95% bound to plasma proteins (DRUG INTERACTIONS. Will have more free drug than should. Only 5-10 percent remain free to produce an effect)
- metabolized by the liver, with metabolites excreatd in urine
- drugs with long “half-lives” (imiparamin-t1/2=24 hours)
- drugs with a relatively small therapeutic index
5 prominent classes of antidepressant drugs:
- Tricyclics
- tertiary amine tricyclics
- secondary amine tricyclics
- Selective Serotonin Reuptake Inhibitors (SSRI)
- Selective Serotonin and Norepinephrine Reuptake Inhibitors (SNRI’s)
- Atypical
- Monomine Oxidase Inhibitors (MAOI’s )
Tricyclics
- attempt to remedy depression by inactivating the “amine” pump on the presynaptic nerve terminal and thus limiting the reuptke of both NE and serotonin.
- Unfortunately, many also have effects at muscarinic receptors, histamine type-1 receptors and alpha-1 receptors
- 2 general types of tricyclics:
- tertiary amine tricyclics
- secondary amine tricyclics
Tertiary amine tricyclics:
bind to the serotonin transporter, which is the predominant binding affinity…
Serontonin is a very complex system, when there is an increase serotonin there is a decrease in appetite….increase in mood..decrease sex libido and function and increase sedation.
-modulatory NT..works with other neurotransmitters, which means that it works with glucomate..NA, etc..no autonomic s/e…
-if the drug interfers with libido or sexual s/e will cause non compliance..you need a good profile on these pt
Secondary Amine Tricyclics:
have affinity for serotonin and an added affinity for NE transporter…increase BP..decrease appetite..increase alertness…anti SLUDE effects
Name 5 tertiary amine tricyclics:
- Amitryptyline (Elavil)
- Clomipramine (Anafranil)
- Doxepin (Sinequan)
- imipramine (Tofranil)
- trimipramine (surmontil)
Amitryptyline (Elavil)
- Tertiary amine tricyclics
- can be given IM
Clomipramine (Anafranil)
- tertiary amine tricyclics
- usually given for obsessive-compulsive d/o (OCD); not very selective, can cause seizures
Doxepin (Sinequan)
- tertiary amine tricyclic
- increased sedation, but absence of cardiovasculare s/e
imipramine (tofranil)
- tertiary amine tricyclic
- can be given IM and a long-acting “pamoate” formulation is available
trimipramine (Surmontil)
- tertiary amine tricyclic
- very sedating and moderately anticholinergic
- opposite SLUDE
Name 5 Secondary Amine Tricyclics
- Amoxapine (Asendin)
- Desipramine (Norpram)
- Maprotiline (Ludiomil)
- Nortryptyline (Pamelor)
- Protryptyline (Vivactil)
Amoxapine (Asendin)
secondary amine tricyclics
a dibenzodiazepine that is a metabolite of the antipsychotic loxapin; therefore, it has a dopaminergic as well as adrenergic mechanism
desipramine (Norpram)
-secondary amine tricyclics
naturally occurring metabolite of imipramine
maprotiline (ludiomil)
secondary amine tricyclics
very new with increased potential for seizures